Dr. Hebert believes that variation within a species is reduced by the evolutionary mechanism called a selective sweep.

The other methods for detecting adaptive evolution use genome wide approaches, often to look for evidence of selective sweeps.

It can, however, be exploited as a method for detecting the action of natural selection via selective sweeps.

Background selection is the opposite of a selective sweep.

For example, biologists try to infer which genes have been under strong selection by detecting selective sweeps.

Whether or not a selective sweep has occurred can be investigated in various ways.

A study of genetic variation among 269 humans found evidence for selective sweeps on chromosomes 1, 2, 4, 8, 12, and 22.

White maize lines had increased diversity and no evidence of linkage disequilibrium associated with a selective sweep.

Another example of the role of selective sweeps in domestication comes from the chicken.

There appears to have been a selective sweep in Africa which reduced the incidence of this antigen there.